The smallest yet most abundant species of cetacean to be found in our coastal waters reaching lengths of 1.5m (5ft). They have blunt heads with a small beak, a very small triangular fin and are grey in colour. They are usually seen in small groups of 2-6 animals but larger groups are often seen. It may be found anywhere there are shallow seas but particularly around the Hebrides and Northern Isles. The animals tend to gather together in pods of 2 to 5. They are possibly the shortest-lived cetacean and rarely live for longer than 12 years. Their body length averages 1.4-1.9m and weight is 55-65kg. Harbour porpoises are a greyish colour. They have a low, triangular dorsal fin and lack a beak. They have spade-shaped teeth (as opposed to conical in dolphins).

Length: Up to 1.8 metres (females slightly larger than males)

Range: Coastal waters of North Atlantic and Pacific

Threats: Caught in fishing nets, pollution

Diet: Variety of fish, shrimps and squid

Of all cetaceans they have the shortest lifespan.  Capable of reaching up to 20 years, but rarely do, the average life is around ten.  Sexual maturity is reached at three to four years with females gestating for approximately 11 months.  Only one calf is born annually, which means the porpoises reproductive life is extremely short.  Calves are born at around 70 centrimetres long and have a strong bond with their mother.  Males play no part in the upbringing of the offspring.  Weaning can ocur quickly and individuals as young as six months have been known to become independent.  With such a short lifespan and reproductive life harbour porpoises are highly susceptible to sudden decreases in local populations